A motion vector field (MVF) is used to precisely describe motion vector information of a picture relative to another picture. Given a to-be-coded picture and a reference picture, an MVF of the to-be-coded picture relative to the reference picture includes a motion vector of each unit in the to-be-coded picture, in the reference picture. The unit is a 1×1 pixel unit, or a pixel unit with a size of 2×1, 1×3, 3×4, or the like.
An inter-frame coding technology based on an MVF generally includes the following steps. An encoder first performs motion estimation to generate an MVF, then performs a motion compensation prediction (MCP) operation based on the MVF and a reference picture to obtain a prediction signal of a to-be-coded picture, then obtains a residual signal of the to-be-coded picture through computation according to a picture signal of the to-be-coded picture and the prediction signal of the to-be-coded picture, and performs transformation, quantization, and entropy coding operations on the residual signal of the to-be-coded picture.
In an existing MCP solution based on an MVF, only one reference picture can be used. When a residual of the to-be-coded picture relative to the reference picture is large, the video coding technology provided by other approaches leads to low coding efficiency.